Automatic transmissions generally include at least one planetary gear set and a plurality of shift elements. The shift elements selectively engage components of the planetary gear sets in order to hinder or prevent rotation of the components. Selective actuation of the shift elements adjusts the gear ratio of the automatic transmission and shifts the automatic transmission between its various gears.
Certain automatic transmissions include dog clutch shifting elements. During various gear shifts, the dog clutch is engaged or closed. Engaging the dog poses certain challenges. For example, certain dog clutches are hydraulically actuated. However, creating and maintaining the hydraulic pressure necessary to actuate the dog clutch can be difficult. In addition, hydraulically actuated dog clutches can require compliance with strict cleanliness guidelines in order to prevent debris from negatively affecting performance of the dog clutch. Further, hydraulically actuated dog clutches generally include O-rings, drilled passageways through cast materials and other components that can necessitate a complex transmission design.
Accordingly, an automatic transmission with features for assisting with actuating a shifting element of the automatic transmission would be useful. In particular, a dog clutch with features for assisting with actuating the dog clutch without hydraulic fluid would be useful.